1805 Series Relief Valves

Bulletin 71.4:1805

Type 1805-2

P1026

1805 Series Relief Valves

Introduction

The 1805 Series relief valves are designed for use in farm tap applications where a safety relief valve is needed between the first and second stage regulators. The 1805 Series is suitable for natural gas, air,

propane, or any operating medium that is not corrosive to the internal parts. Relief pressures range from 5 to 125 psig / 0,34 to 8,6 bar. Maximum pressure, including buildup, is 150 psig / 10,3 bar.

Features

• Tight Shutoff—Provided by the Nitrile (NBR)

O-ring and O-ring seat.

• Easy Maintenance—The union nut allows quick

removal of the cage assembly for trim inspection. The valve can be back in operation in a matter of minutes.

• Simple Adjustment—A single adjusting screw is

used to meet individual application requirements.

• Complete Venting—A closing cap is available if

all venting must be piped away.

• Sour Gas Service Capability—Optional materials

are available for applications handling sour gases. These constructions comply with the

recommendations of the NACE International Standards MR0175 and MR0103.

Figure 1. Typical 1805 Relief Valves

Type 1805-4

Bulletin 71.4:1805

Specifications

Body Sizes and End Connection Style

3/4, 1, 1-1/2, or 2 NPT

Maximum Inlet Pressure(1)

150 psig / 10,3 bar including buildup

Relief Valve Set Pressure Ranges

See Table 1

Flow and IEC Sizing Coefficients

See Table 3

Temperature Capabilities(1)

-20° to 150°F / -29° to 66°C

Construction Materials

Body: Cast Iron (all sizes) and Ductile Iron (NACE)

(3/4 and 1 NPT body sizes)

Diaphragm: Nitrile (NBR) Valve Guide Orifice: Aluminum O-Ring Washer: Stainless steel O-Rings: Nitrile (NBR)

O-Ring Holder: Aluminum Diaphragm Plate: Brass Upper Spring Seat: Plated steel Union Nut: Ductile Iron

Vent Screen: Stainless steel Approximate Weights

3/4 to 1 NPT bodies: 5 pounds / 2 kg 1-1/2 to 2 NPT bodies: 13 pounds / 6 kg

1. The pressure/temperature limits in this Bulletin or any applicable standard limitation should not be exceeded.

BODY SIZE, NPT

RELIEF PRESSURE RANGE

SPRING PART

NUMBER SPRING COLOR CODE

SPRING FREE LENGTH SPRING WIRE DIAMETER psig bar Inches mm Inches mm

3/4 or 1 10 to 605 to 35 20 to 125 0,34 to 2,4 0,69 to 4,1 1,4 to 8,6 1B986027212 1B788327022 1B788427022 Green Silver Blue 2.25 2.13 1.94 57,2 54,1 49,3 0.12 0.14 0.18 3,05 3,56 4,57 1-1/2 or 2 10 to 505 to 20 35 to 125 0,34 to 1,4 0,69 to 3,4 2,4 to 8,6 1D892327022 1D665927022 1E543627142 Red Blue Yellow 2.94 2.50 2.31 74,7 63,5 58,7 0.17 0.22 0.28 4,32 5,59 7,11

Table 1. Relief Valve Set Pressure Ranges

TYPE NUMBER BODY SIZE AND END _{CONNECTION, NPT} DISTINCTIVE CONSTRUCTION FEATURES

1805-2 3/4 or 1 Cast iron spring case, closing cap with 1/4 NPT vent placed over the adjusting screw 1805-3 1-1/2 or 2 Cast iron spring case, closing cap with 1/4 NPT vent placed over the adjusting screw 1805-4 3/4 or 1 Cast iron spring case

1805-5 1-1/2 or 2 Cast iron spring case

1805-7 3/4 or 1 Cast iron spring case, closing cap with 1/4 NPT vent placed over the adjusting _{screw, and screen in outlet}

Table 2. Available Constructions

BODY SIZE, NPT C1 Km

IEC SIZING COEFFICIENTS XT FD FL 3/4 to 1

35 0.79 0.73 0.39 0.89

1-1/2 to 2 0.94 0.44

Bulletin 71.4:1805

Type XXXX

Month Year

Type XXXX

TANK PRESSURE VACUUM PRESSURE PRE-EXPANSION PRESSURE INTERMEDIATE BLEED PRESSURE PILOT SUPPLY PRESSURE INTERMEDIATE PRESSURE LOADING PRESSURE PUMP PRESSURE BYPASS PRESSURE BACK PRESSURE INLET PRESSURE OUTLET PRESSURE ATMOSPHERIC PRESSURE VACUUM PRESSURE PRE-EXPANSION PRESSURE INTERMEDIATE BLEED PRESSURE PILOT SUPPLY PRESSURE

BYPASS PRESSURE BACK PRESSURE PUMP PRESSURE BOOST PRESSURE

EXHAUST

PILOT LOADING PRESSURE VENT HEADER PRESSURE INLET BLEED PRESSURE

VALVE GUIDE ORIFICE BODY O-RING O-RING WASHER O-RING HOLDER VALVE SEAT UNION NUT DIAPHRAGM HEAD UPPER SPRING SEAT DIAPHRAGM O-RING

Figure 2. 1805 Series Operational Schematic A6671

Principle of Operation

See Figure 2. Relief valves respond to changes in upstream pressure. If upstream pressure increases and exceeds the relief valve setting, the valve will open and allow gas to vent to the atmosphere. When upstream pressure returns to normal level (below the setting of the relief valve), the relief valve automatically closes and normal system operation resumes.

In the 1805 Series relief valves, the upstream pressure registers underneath the diaphragm. Gas reaches the diaphragm through the space between the O-ring holder and the valve guide orifice in 3/4 and 1 NPT bodies or through registration holes in the valve guide orifice in 1-1/2 and 2 NPT bodies.

When the upstream pressure increases beyond the spring setting, the force underneath the diaphragm overcomes spring compression. The O-ring holder moves upward, carrying the O-ring away from the valve seat. This opens the flow line, allows gas to flow to the atmosphere, and relieves the overpressure condition. When upstream pressure registered on the diaphragm decreases to a level below that of the spring setting of the relief valve, the spring force pushes the diaphragm plate and O-ring holder toward the valve seat. Contact between O-ring and valve seat prevents further flow to atmosphere.

Type XXXX

MXXXX

INLET PRESSURE OUTLET PRESSURE ATMOSPHERIC PRESSURE

Month Year

Type XXXX

TANK PRESSURE VACUUM PRESSURE

PRE-EXPANSION PRESSURE INTERMEDIATE BLEED PRESSURE PILOT SUPPLY PRESSURE

INTERMEDIATE PRESSURE LOADING PRESSURE PUMP PRESSURE BYPASS PRESSURE BACK PRESSURE INLET PRESSURE OUTLET PRESSURE ATMOSPHERIC PRESSURE VACUUM PRESSURE PRE-EXPANSION PRESSURE INTERMEDIATE BLEED PRESSURE PILOT SUPPLY PRESSURE

BYPASS PRESSURE BACK PRESSURE PUMP PRESSURE BOOST PRESSURE

EXHAUST

PILOT LOADING PRESSURE VENT HEADER PRESSURE INLET BLEED PRESSURE

INLET PRESSURE

Bulletin 71.4:1805

1. SETPOINT IS TO BE INTERPRETED AS BUBBLE POINT

*MAXIMUM PRESSURE INCLUDING BUILDUP - 150 psig / 10,3 bar AT 150°F / 66°C.

3/4 AND 1 NPT BODIES / 10,3 / 8,6 / 6,9 / 5,2 / 3,4 / 1,7 / 10,3 / 8,6 / 6,9 / 5,2 / 3,4 / 1,7 / 10,3 / 8,6 / 6,9 / 5,2 / 3,4 / 1,7 150 100 125 75 50 25 50 / 3,4 SETPOINT(1) 75 / 5,2 125 / 8,6 100 / 6,9

INLET PRESSURE (SETPOINT PLUS BUILDUP),

psig / bar 150 125 100 75 50 25 150 125 100 75 50 25 60 / 4,1 50 / 3,4 40 / 2,8 25 / 1,7 SETPOINT (1) 35 / 2,4 25 / 1,7 20 / 1,4 10 / 0,69 5 / 0,34 SETPOINT (1) 0 / 5 / 10 / 15 / 20 / 25 / 30 / 35 / 40 / 0 0,13 0,27 0,40 0,54 0,67 0,80 0,94 1,07 SPRING 1B788427022 SPRING 1B788327022 SPRING 1B986027212 B0812 / 10,3 / 8,6 / 6,9 / 5,2 / 3,4 / 1,7 1-1/2 AND 2 NPT BODIES 150 125 100 75 50 25

INLET PRESSURE (SETPOINT PLUS BUILDUP),

psig / bar 125 / 8,6 100 / 6,9 75 / 5,2 60 / 4,1 50 / 3,4 SETPOINT(1) 50 / 3,4 40 / 2,8 30 / 2,1 20 / 1,4 SETPOINT(1) 5 / 0,34 SETPOINT(1) 10 / 0,69 20 / 1,4 0 / 20 / 40 / 60 / 80 / 100 / 120 / 140 / 160 / 180 / 200 / / 10,3 / 8,6 / 6,9 / 5,2 / 3,4 / 1,7 / 10,3 / 8,6 / 6,9 / 5,2 / 3,4 / 1,7 150 125 100 75 50 25 150 125 100 75 50 25 0,54 1,07 1,61 2,14 2,68 3,22 3,75 4,29 4,82 5,36 0 SPRING 1E543627142 SPRING 1D665927022 SPRING 1D892327022

Figure 3. Relief Capacity Curves

CAPACITY IN THOUSAND SCFH, AT 60°F AND 14.7 psia /

Nm3_{/h, AT 0°C AND 1,01325 bar OF 0.6 SPECIFIC GRAVITY}

Bulletin 71.4:1805

Installation

The 1805 Series relief valves may be installed in any position. However, the outlet connection and vents must be protected against the entrance of rain, snow, insects, or any other foreign material that may plug the outlet or affect the opening and closing of the valve. If it is necessary to pipe away the outlet, remove the outlet screen (if one is present).

Flow through the valve must be as indicated by the flow direction arrow on the body. For dimensional information, see Figure 5.

Capacity Information

Natural gas relieving capacities at selected inlet pressures (setpoint plus buildup) are given in Figure 3. Flows are in thousands SCFH (60°F and 14.7 psia) of 0.6 specific gravity natural gas. To determine the equivalent capacities for other gases, multiply the capacity obtained from the curves by the following appropriate conversion factor: 0.775 for air, 0.789 for nitrogen, 0.625 for propane, or 0.548 for butane. For gases of other specific gravities, multiply the given capacity by 0.775, and divide by the square root of the appropriate specific gravity.

Then, if capacity is desired in normal cubic meters per hour (Nm3_{/h) at 0°C and 1,01325 bar, multiply values}

obtained from Figure 3 by 0.0268.

Overpressure

Relief pressure ratings are from 5 to 125 psig / 0,34 to 8,6 bar. The maximum inlet pressure, including buildup, is 150 psig / 10,3 bar. System operation within these limitations does not eliminate the possibility of damage from external sources or from debris in the gas line. The relief valve should be inspected for damage regularly and after any overpressure condition.

Universal NACE Compliance

Optional materials are available for applications handling sour gases. These constructions comply with the recommendations of NACE International sour service standards.

The manufacturing processes and materials used by Emerson assure that all products specified for sour gas service comply with the chemical, physical, and metallurgical requirements of NACE MR0175 and/or NACE MR0103. Customers have the responsibility to specify correct materials. Environmental limitations may apply and shall be determined by the user.

W1258

Bulletin 71.4:1805

Figure 5. 1805 Series Dimensional Drawings

TYPE 1805-4 OR 1805-5 WITHOUT CLOSING CAP TYPE 1805-2, 1805-3, OR 1805-7 WITH CLOSING CAP

AF2211 D C B A 1/4 NPT D C B A AH6967

TYPES END CONNECTION BODY SIZE AND

STYLE, NPT MATERIAL DIMENSION, INCHES / mm A B C D / max 1805-2/ 1 1805-4 1805-7/ 1 3/4 Cast iron 3.62 / 92 1.81 / 46 1.00 / 25 6.44 / 164 Ductile iron / NACE 3.88 / 99 1.94 / 49 1.38 / 35 6.44 / 164 1 Cast iron 3.62 / 92 1.81 / 46 1.00 / 25 6.44 / 164 Ductile iron / NACE 3.88 / 99 1.94 / 49 1.38 / 35 6.44 / 164 1805-3/ 1

1805-5

1-1/2 Cast iron 5.88 / 149 2.94 / 75 1.69 / 43 9.12 / 232 2 Cast iron 5.88 / 149 2.94 / 75 1.69 / 43 9.12 / 232

1. With closing cap.

Bulletin 71.4:1805

Regulators Quick Order Guide

* * * Readily Available for Shipment * * Allow Additional Time for Shipment

* Special Order, Constructed from Non-Stocked Parts. Consult your local _{Sales Office for Availability.}

Ordering Information

Please give the following information when ordering any of the 1805 Series relief valves:

1. Type Number

2. Body Size and Material

3. Desired Relief Pressure Range

Ordering Guide

Type (Refer to Table 2 for Construction Features)

(Select One) 1805-2*** 1805-3*** 1805-4** 1805-5*** 1805-7***

Body Size and End Connection Style (Select One)

3/4 NPT*** 1 NPT*** 1-1/2 NPT** 2 NPT***

Body Material (Select One)

Cast Iron (All sizes)**

Ductile Iron (NACE) (3/4 or 1 NPT body size only)**

Specification Worksheet Application:

Specific Use Line Size

Gas Type and Specific Gravity Gas Temperature

Relief Valve Size:

Brand of upstream regulator? Orifice size of the upstream regulator?

Wide-open coefficient of the upstream regulator?

Pressure:

Maximum Inlet Pressure (P1max)

Minimum Inlet Pressure (P1min)

Downstream Pressure Setting(s) (P2)

Maximum Flow (Q_max)

Performance Required:

Accuracy Requirements?

Need for Extremely Fast Response?

Other Requirements:

Relief Set Pressure Range (Select One) 3/4 or 1 NPT Body Size:

5 to 35 psig / 0,34 to 2,4 bar, Green*** 10 to 60 psig / 0,69 to 4,1 bar, Silver*** 20 to 125 psig / 1,4 to 8,6 bar, Blue***

1-1/2 or 2 NPT Body Size:

5 to 20 psig / 0,34 to 1,4 bar, Red*** 10 to 50 psig / 0,69 to 3,4 bar, Blue*** 35 to 125 psig / 2,4 to 8,6 bar, Yellow***

Replacement Parts Kit (Optional)

Bulletin 71.4:1805

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The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. We reserve the right to modify or improve the designs or specifications of such products at any time without notice.

For further information visit www.fisherregulators.com

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